Fusible attachment plug



Sept. -13, 1932.

E. ADAMS FUSIBLE ATTACHMENT PLUG Filed May 9, 1951 Patented Sept. 13,

fUNITED STATES PATENT OFFICE i ERVIN ADAMS, F MOUNT CARMEL, PENNSYLYANIA, ASSIGNOR TO lHENRY W.

, BBECKEB, OF MOUNT CARMEL, VPENNSYLVANIA FUBIBLE ATTACHMENT PLUG Application led lay 9, 1931. Serial No. 536,253.

tect thelparticular appliance in use, and

being composedof sections which may beI easily and uickly disassembled to replace a blownout use. y

A further object is to provide a fusible attachment plugin which tight connections are maintained at all times betweenthe terminals carried by the sections, so that the device will withstand severe conditions of service.

A still further object is to provide a fusible attachment plug which will receive standard fuses of various capacities and will include telescopic sections forming a complete closure around the fuse while, at the same time, being capable of being quickly withdrawn from each other to expose the fuse for replacement by simply unscrewing a single collar'f,

With the above and` other objects in view the invention resides in certain novel details of construction and combinations of parts hereinafter fully described and claimed, it

being understood that various modifications 2 is to be used with, there being spring tongues may be resorted to withinthe scope of the appended claims without departing from the spirit or sacrificing any yof the advantages of the invention. y

In the accompanying drawing forming part of this specification,

Figure 1 is a perspective view of a fusible attachment plug constructed in accordance with my invention,

Fig. 2 's an enlarged longitudinal sectional viewf-t rough the plug, and

Fi 3 is a cross sectional view taken on the l1ne 3--3 of Fig. 2. v

Referring now-to the drawing in which like characters of reference designate similar parts in the various views, the device is shown to comprise a pair of cylindrical shells 10 and 11, each having an open end, as shown best in Fig. 2. The shells, opposite the open ends thereof, are provided with end walls 12 and 13, respectively, which are of greater thickness than the side Walls of the shells to provide mountingsfor the electric terminals. The inner shell 11 is of suiiicient diameter to telescope snugly into the outer shell 10. A flanged collar 14 is threaded onto the open end of the outer shell, as shown at 15, and overlaps the end wall of the inner shell to unite the shells. Preferably, the collar is countersunk in b'oth shells to provide a smooth, continuous exterior surface for the plug. The shells and collar are preferably formed of bakeliteor other suitable insulating material.

The inner shell 11 is uniformly reduced at the inner end ofthe bore thereof to providev a cylindrical chamber 16 in which is permanently mounted a threaded metal socket 17 into which may be screwed a standard fuse plug 18 of the usual type. The metal socket 17 is preferably attached to the inner face of the end wall of the shell 11 by means of screws 19 arranged in an annular series around a central boss 20 which projects from said inner face.

The end wall of the outer shell 10 is provided with a pair of slots 21 to receive the prongs of the' attaching plug of whatever electrical device the fusible attachment plug 22 in the slotspermanently secured in place by screws 23, these tongues being adapted to clamp said prongs in the slots in the usual and well-known manner.

The end wall 13 of the inner shell 11 is preferably provided centrally with a countersink. 24 in which is bolted, as shown at 25, a pair of prongs 26 adapted tobe received in the slots of an electrical socket, such as a wall socket, Hoor socket, or electric iixture socket, from which the electrical appliance isto be supplied with current. v

To electrically connect the fuse in circuit with the prongs 26 and spring tongues 22, the outer shell 12 is provided with a pair of substantially L-shaped metal leaves 28, one leg of each leaf being exposedand extending longitudinally along the inner faceof the bore of the shell, and the other leg beingdirected inwardly through the end'` wall of )ce the shell and attached underneath the secured ends of the tongues 22 by means of the screws 23 which mount said tongues.

Likewise, the inner shell 11 is provided with a pair of L-shaped leaves 29, one leg of each leaf being exposed exteriorly upon the outer surface of the shell andpreferably being countersunk therein and so arranged as to have wiping contact with the corresponding legs of the metal leaves carried by the outer shell 10. It will be observed that one ofthe leaves 29 has one leg thereof directed inwardly to extend along the inner face ofthe end wall of the inner shell` 11 and is secured thereto by means ofnone of the above-mentioned bolts 25 which attaches one of the prongs 26 to the shell. The other leaf 29 is considerably shorter than the rst-mentioned leaf 29 and has one leg thereof passed through the wall of the inner shell at a point substantially midway between the ends of the shell, the leafterminating in a lip 30 which is countersunk in the wall of the bore of the shell and frictionallyhears against the above-mentioned metal screw socket 17.

To complete the electrical connection, a substantially Z-shaped leaf 31 has one leg secured to the inner face of the end wall of the inner shell 11 by means of the bolt 25 which attaches the adjacent prong 26 to the shell, the

' opposite terminal of the leaf being resilient and extending obliquely across the abovementioned boss 20 into the socket 17 and frictionally engaging the center terminal of the fuse plu 18.

By re erring to Fig. 2, electrical connections may be traced from the left prong 26 through the bolt 25, leaf 29, leaf 28, and'spring tongue 22 on the left side of the device, as shown in Fig. 2. On the right side of the illustration of the device as shown in Fig. 2, electrical connections may be traced through the prong 26, bolt 25, Z-shaped leaf 31, fusible element 32 of the fuseplug 18, metal screw socket 17, leaf 29, leaf 28, and spring tongue 22.

By now referring to Fig. 3, it will be seen that to prevent relative rotation of the shells, preferably the outer shell is provided on the inner face of the bore thereof with a longitudinal rib 33 which engages in a corresponding longitudinal slot 34 formed on the outer surface of the inrer shell 11, as best shown in Fig. 3. -f From the a'bove description it will be obt served that both shellsmay be detached from each other by simply unscrewing a single collar'14 to expose the fuse plug 18 for replacement when blown. lt will be further observed that the fuse plug is completely housed on all sides by the shells. It will still further be observedthat the L-shaped leaves forming the terminals, as above described, have wiping contact with each other so that positive electrical connections will be maintained at all times under the most severe conditions of service. It will further be pointed out that said leaves overlap each other sufficiently to insure adequate electrical .connections therebetween at all times.

In operation, of course, a fuse plug 18 of predetermined capacity is always used to protect the articular electrical apparatus being used. or example, it is desirable at times to employ a three-ampere fuse, at other times a five or six ampere, while still again it may be necessary to use a fuse plug of still greater capacit according to the amount of current whic the particular appliance draws. It will be observed that the bore of the inner shell is of sufficient diameter to permit of the fuse lug being screwed into and out of the meta screw socket 17 after the shells have been disassembled.

Having thus described the invention, I claim:

1. A fusible attachment plug comprising telescoped shells detachably secured together, a metal screw socket carried by one of the shells for receiving a standard fuse plug, prongs carried by one of the shells, spring tongues carried by the other shell in slots formed in the shell, overlapping leaves carried by the shells having wiping contact with each other for electrically connecting the prongs and tongues in series with said socket, and a spring tongue carried by one of the shells and projecting into said socket for connecting the center terminalV of the fuse plug with one of said prongs.

2. A `fusible attachment plug comprising telescoped shells removably secured together in non-rotatable relationship, overlapping spring leaves forming electrical terminals having wiping contact with each other and carried by respective-shells, a metal screw socket carried by one of the shells for removably receiving a standard fuse plug, a spring tongue carried by the last-named Shell projecting into the socket, prongs carried by one of the shells, and springs tongues carried by .the other she1l,`-the prongs and shells being electrically connectedin series with said socket by means of said overlapping spring leaves and the first-named spring tongue.

3 A fusible attachment plug comprising telescoped shells having a longitudinal tongue and groove connection to prevent relative rotation, a collar removably secured to one of the shells and `overlapping the end of the other shell to confine the shells together, a fuse plug housed completely by the shells and removabl prongs carrie by one of the shells, there being slots in the-other shell having spring tongues concealed therein, and means electrisecured to one of the shells,

cally connecting the fuse plug in series with the prongs and tongues.

4. A fusible attachment plug comprising telescoped shells each having one end closed telescoped shells, means securing the shells to `and the opposite end'open, the open end of each shell being turned toward the closed end of the opposite shell, a collar threaded on the open end of one shell and overlapping the closed end of the other shell to removably secure the shells together, a fuse plug housed completely by the shells and removably secured to one of the shells, prongs carried by one of the shells, there being slots in the other shell, spring tongues confined in said slots, and means'electrically connecting the fuse plug in series with the prongs and tongues.

5. A fusible attachment plug comprising gether, means preventing relative rotation of the shells, prongs carried bythe inner shell, there being slots in the outer shell, spring tongues in said slots., pairs of L-shaped leaves carried by the shells having wiping contact with each other, one pair of said leaves electrically connecting ythe prong and corresponding tongue'on one side of each shell together, a metal screw socket carried by the inner shell adapted to receive a standard fuse plug, the other pair of L-shaped leaves electrically con# necting the socket with the remaining spring tongue on the opposite side of the outer shell, and a metal' leaf electrically connected to the remaining prong carried by the inner shell and extending into the screw socket for contact with the center terminal of said fuse plug.

In testimony whereof I ax m signature.

ERVIN yADAM [1.. 8.] 

